Availability of widely harmonized mobile spectrum is crucial for the success of 5G mobile communications, fulfilling the visions and requirements and delivering the full range of potential capabilities for 5G. This article introduces the global situation of spectrum for 5G, both below and above 6 GHz, in both the regulatory status and technical aspects. In particular, the technical challenges of supporting 5G in millimeter-wave spectrum, such as coverage limitation and implementation aspects, are discussed.